Versa Max 3 
AQUAEL filter sponge cartridges are made from carefully selected phenol-free sponge. These cartridges ensure effective mechanical filtration of the water, retaining impurities and visible debris.
At the same time, it is considered a basis for nitrifying bacteria, making it also perform the function of biological filtration. To ensure optimal operation of the cartridges, it is recommended to replace them regularly and keep them only in "old" water taken during aquarium water changes.